The only was an emerald jewel wasp can reproduce is by using a cockroach as a host for its larvae.
The wasp delivers a sting to the roaches brain and lays its eggs. When they hatch they use the ‘zombie’ cockroach as food.
Vanderbilt University biologist Ken Catania found far from being a weak-willed sap easily paralyzed by the emerald jewel wasp’s sting to the brain – followed by becoming a placid egg carrier and then larvae chow – the cockroach can deliver a stunning karate kick that saves its life.
Catania says, “the cockroach has a suite of behaviours that it can deploy to fend off the zombie-makers, and this starts out with what I call the ‘en garde’ position, like in fencing.”
“That allows the roach to move its antenna toward the wasp so it can track an approaching attack and aim kicks at the head and body of the wasp, and that’s one of the most efficient deterrents.
On its Youtube post, Vanderbilt University says the good news for the cockroach: the defence worked for 63 percent of adults that tried it. The bad news: juveniles almost always failed and got the stung in the brain.